Improvement in endless-chain propellers



L. ALVORD. *ENDLESS-CHAIN PROPELLER.

$10,174,178. Patented Feb. 29, 18-76.

rank/ UNITED STATES PATENT Or'r'rca LUTHER ALVORD, OF SOUTH HADLEY FALLS, MASSACHUSETTS.

lMPROVEMENT IN ENDLESS-CHAIN PROPELLERS.

. Specification forming part of Letters Patent No. 174, 178, dated February 29, 1876; application filed August 30, 1875.

To all whom it may concern:

Be it known that I, LUTHER ALVORD, of South Hadley Falls,-State of Massachusetts, have invented a new Device for 'Propelling Vessels, of which the following is a specification: q

The nature and objects 'of my invention are illustrated in the following drawings and descriptionr;

Figure Igis a side view, Fig. II a plan view,

- and Figiz'III a detailed view, of my invention.

Thisinvention consists, generally, of a series of blades connected to form anendless apron or railway, which, moving .over rollers at both of its ends attatched to the bQttOlIIOf the boat, acts directly upon the water to produce the desired propulsion.

These blades are connected through side links by rods, which form hinges to permit them to change their direction over the rollers, while projecting ends of.said rods engage i I with depressions in the perimeters'of the rolls find a-bearing within the recesses.

It will be seen that when the power is applied through a crank or other well-known way to the driving-roll A, the series of blades is set inrmotion through said driving-roll,

while following upon the roll B with little friction. H

In Fig. II it is seen that the links 71., which give the required'flexibility to the series of blades D, are united to each other and to the blades by the transverse rods g, which, be

sides forming these hinges, and alfording the ends (1 to engage with the rolls A B, serve to 'brace the apron of blades laterally, and by passing through the apex of each blade,

when constructed as shown in Fig. III, to

hold each in its proper relative position.

In practice, I form upon the outside of rolls A B outside flanges, which, being of equal diameter with the rolls containing the recesses b, cover the sides of said recesses and form sockets to protect the ends d and'thc recesses themselves from being obstructed by foreign matter.

If the entire railway of blades was susthe upper half withinthe vessel, so that the water acted upon by its blades will be in effect confined, though if desired the blades may be made to feather in one direction.

In arranging this device upon the bottoms of boats, the railway may be inclined in a vertical plane, so that each'blade will be act ing upon a diflerent stratum of water from the one next to it, to thus avoid any di'sad vantage from acting upon water already in motion.

The water escaping behind'a boat employing this device for propulsion will not ,make a wash that could efl'ect a-canal-bank, and it will be effective upon extensible supports, from a boat when designed to deepen bars and channels, either by direct contact with the bottom or by creating a scour from close vicinity thereto.

I am aware that various propellers have been constructed upon the principle of an endless chain of buckets or floats, and make no claim to such principle; but by my special construction and arrangement of parts the chain of floats, while flexible in the required direction is, by the'union of the transverse rods, links, and floats, having their sides united to the rods in the form of braces, so trusscd as to, while confining the water with- ,in the floats, resist to the greatest extent in proportion to its weight all strain, lateral or direct, from the resistance of the water or of any obstruction of any sand. or mud it may be designedly brought in contact with when used to deepen channels.

Having now describedmy invention, what I claim is- .The propeller for boats, consisting of the blades D, rods 9, links it, and rolls A B, when all constructed and arranged as set forth.

LUTHER ALVORD. Witnesses:

R. F. HYDE,

T. M. BROWN. 

